feat: replace elizacp with Testy, a minimal internal test agent

Remove the elizacp crate (published to crates.io) and replace it with
Testy, a simple JSON-command-based test agent built into sacp-test
(publish = false).

Testy accepts typed TestyCommand values serialized as JSON prompts:
- Greet: responds with "Hello, world!"
- Echo: echoes a message back
- CallTool: invokes an MCP tool by server/name
- ListTools: lists tools from an MCP server

This eliminates ~3500 lines of Eliza chatbot engine that was overkill
for integration testing purposes.

BREAKING CHANGE: elizacp crate is removed from the workspace

Author: nikomatsakis

.github/workflows/release-binaries.yml

@@ -3,7 +3,6 @@ name: Release Binaries
 on:
   push:
     tags:
-      - "elizacp-v*"
       - "yopo-v*"
       - "sacp-conductor-v*"
       - "sacp-tee-v*"

Cargo.toml

@@ -6,7 +6,6 @@ members = [
     "src/sacp-derive",
     "src/sacp-tokio",
     "src/sacp-rmcp",
-    "src/elizacp",
     "src/sacp-test",
     "src/yopo",
     "src/sacp-trace-viewer",

README.md

@@ -32,8 +32,8 @@ This repository contains several crates:
 - **[`sacp-proxy`](./src/sacp-proxy/)** - Framework for building ACP proxy components
 - **[`sacp-conductor`](./src/sacp-conductor/)** - Binary that orchestrates proxy chains
 
-**Examples & Testing:**
-- **[`elizacp`](./src/elizacp/)** - Example ACP agent implementing the classic Eliza chatbot (useful for testing)
+**Testing:**
+- **[`sacp-test`](./src/sacp-test/)** - Test utilities, fixtures, and a built-in test agent
 
 ## Documentation
 

justfile

@@ -1,7 +1,7 @@
 # Build binaries needed for integration tests
 prep-tests:
     cargo build -p sacp-conductor
-    cargo build -p elizacp
+    cargo build -p sacp-test --bin testy
     cargo build -p sacp-test --bin mcp-echo-server --example arrow_proxy
 
 # Run all tests (requires prep-tests first)

md/introduction.md

@@ -28,7 +28,6 @@ src/
 ├── sacp-conductor/    # Conductor binary and library
 ├── sacp-test/         # Test utilities and fixtures
 ├── sacp-trace-viewer/ # Trace visualization tool
-├── elizacp/           # Example agent implementation
 └── yopo/              # "You Only Prompt Once" example client
 ```